Single Molecule Biophysics Contributed Talks MEASUREMENTS OF BIOMOLECULAR INTERACTIONS IN PHARMACEUTICAL & IMMUNODIAGNOSTIC SYSTEMS

Recent advances in the immunodiagnostics and pharmaceutical industries have demanded an improved understanding of the molecular interactions that underpin their technologies. For example, the design of more efficacious therapeutic agents requires a detailed knowledge of the proposed target biomolecule or biomolecular interaction. Techniques with the ability to probe single biomolecular interactions, such as the atomic force microscope (AFM), provide a new approach for the direct investigation of such processes at a fundamental level. In previous studies, we have employed AFM force measurements to record interaction forces between the biological molecules employed in a commercial immunoassay system 1−3. More recently, we have employed a similar approach to investigate the influence of the number of epitopes (per protein antigen) in AFM studies of antigen−antibody interactions 4. In addition, interaction forces have been recorded between an anti−human chorionic gonadotrophin antibody (anti−hCG) and a secondary anti− antihCG antibody, and the effect of molecular orientation on the binding force investigated. Such studies require the covalent attachment of biomolecules to the AFM and substrate surface. To this end we have immobilized proteins using either amino−silane chemistry 1 or via a poly (ethyleneglycol) (PEG) polymer tether